Spinning position, air spinning machine and method for producing a yarn

ABSTRACT

A spinning position for producing a yarn from a fed fiber band, having an air spinning nozzle with an inlet opening for the fed fiber band and an outlet area with an outlet opening for the spun yarn is provided. In order to provide a spinning position, an air spinning machine and a method which allow for the yarn surface finish to be modified advantageously without the yarn properties deteriorating at the same time, while also avoiding expensive and complex modifications to the spinning position, there is provision for a navel to be arranged in the outlet area behind the outlet opening for modifying the surface finish of the spun yarn.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from German National Patent Application No. DE 102019111035.1, filed Apr. 29, 2019, entitled “Spinnstelle, Luftspinnmaschine and Verfahren zum Herstellen eines Garns”, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention concerns a spinning position and an air spinning machine for producing a yarn from a fed fiber band, comprising an air spinning nozzle with an inlet opening for the fed fiber band and an outlet area with an outlet opening for the spun yarn. Furthermore, the present invention concerns a method for producing a yarn with a modified surface finish. Finally, the present invention concerns the use of a navel in the outlet area of the air spinning nozzle of a spinning position for modifying the surface finish of an air-spun yarn.

BACKGROUND OF THE INVENTION

Spinning positions and air spinning machines are known from the state of the art in a wide variety of configurations and, in addition to rotor spinning machines, are machines that are frequently used for producing a yarn from a fiber material, in particular from a fiber band fed to the spinning position.

In air spinning, a sliver or fiber band is typically drafted according to the yarn count to be achieved by means of a drafting system comprising several roller pairs and fed to the air spinning nozzle. Inside the air spinning nozzle, a part of the fed fibers is wound around the parallel fiber core by means of a rotational flow. This results in the air-yarn-specific yarn structure of a parallel yarn core with winding fibers attached at a certain angle, which ensure the strength of the yarn. As there are no mechanical points of contact when the rotation of the fibers is input, air-spun yarn usually has a particularly low hairiness.

This low hairiness can have a negative effect after further processing into a textile web or a knitted fabric, for example by resulting in a rough feel. The proportion of protruding fibers can generally be influenced by changing the compressed air supplied for setting the spinning pressure and/or by changing the spinning speed. However, when the spinning pressure and/or spinning speed is/are changed, other properties of the air-spun yarn are also negatively influenced, meaning that better hairiness can indeed be achieved, but the yarn properties, such as yarn stability, will deteriorate generally at the same time.

SUMMARY OF THE INVENTION

The problem addressed by the present invention is therefore one of providing a spinning position, an air spinning machine and a method which allow for the yarn surface finish to be modified advantageously without the yarn properties deteriorating at the same time, while also avoiding expensive and complex modifications to the spinning position.

According to the present invention, the problem is solved by means of a spinning position according to claim 1, an air spinning machine according to claim 9, a method according to claim 10 and through the use of a navel according to claim 11. Advantageous further developments of the present invention are stated in the dependent claims.

The spinning position according to the present invention for producing a yarn from a fed fiber band has an air spinning nozzle with an inlet opening for the fed fiber band and an outlet area for the spun yarn which emerges from an outlet opening in the outlet area. Also according to the present invention, a navel is arranged in the outlet area downstream of the outlet opening in the direction of the yarn take-off for modifying the surface finish of the spun yarn.

An air spinning machine according to the present invention has at least one, preferably several and particularly preferably several identical spinning positions each for producing a yarn from a fed fiber band, in which case the spinning position, of which there is at least one, and preferably all spinning positions are formed according to the present invention.

In the method according to the present invention for producing a yarn with a modified surface finish, air spinning of a yarn from a fiber band by means of an air spinning nozzle is carried out first, followed by guiding of the air-spun yarn through a navel for modifying the yarn surface, which is preferably carried out in the course of taking the yarn off the air spinning nozzle.

Finally, the present invention comprises the use of a navel in the outlet area of an air spinning nozzle downstream of an outlet opening in the direction of a yarn take-off for modifying the surface finish of an air-spun yarn in a spinning position or in an air spinning machine, both in particular according to the present invention.

The inventors have recognized that it is not possible to directly influence the air spinning method, for example by changing the spinning parameters such as the spinning nozzle geometry, the spinning pressure or the spinning speed, without the associated disadvantages in terms of yarn quality. Starting from this position, it is part of the present invention that a surface modification of the air-spun yarn is carried out immediately following the air spinning process, in which case the quality of the air-spun yarn, which is conditional on the spinning method, is not negatively influenced. The present invention thus makes it possible to modify the surface of a spun yarn without intervening in the spinning process, so that firstly the spinning process can be performed with the optimum parameters for this purpose, in particular without taking aspects of the yarn surface finish into account, and subsequently the yarn surface finish can be changed to a desired condition by means of the navel. This enables a significant expansion of the fields of application and the possible uses of air-spun yarn, in particular as knitting yarn with a softer and/or more fibrous or hairy surface, which is advantageous for this purpose.

The spinning position is any unit of a machine, in particular of an air spinning machine, or an independent device intended to produce a yarn from a fiber material and in particular from a fiber band. Accordingly, an air spinning machine is a device with at least one and preferably several spinning positions, in particular spinning positions that are identical to one another, which are provided in each case for producing a yarn from a fiber material by means of air spinning.

The air spinning nozzle basically comprises a component intended for forming the yarn, such as a yarn forming element. In particular, the air spinning nozzle can be an assembly of several components of any air spinning device formed for this purpose. The air spinning nozzle is preferably arranged within a spinning position in this case. In addition, the spinning position can have any other components with any functions. For feeding the fiber material to be air-spun, the air spinning nozzle has an inlet opening through which the fiber material, in particular in the form of a fiber band, can preferably be fed continuously.

Furthermore, the air spinning nozzle has an outlet opening for the finished spun yarn, which is preferably arranged opposite the inlet opening. The outlet opening is arranged in an outlet area of the air spinning nozzle or of a unit having the air spinning nozzle, in which case any other components, in particular for removing the yarn from the air spinning nozzle, can be arranged between the actual air spinning nozzle and the outlet opening, i.e. the area from which the finished air-spun yarn emerges. In a particularly preferable embodiment the outlet opening is a thread channel output at the end of a thread channel assigned to the air spinning nozzle, and in a particularly preferable embodiment the outlet opening is the end of a piecing tube which is arranged downstream of a spinning cone of a yarn forming element of the air spinning nozzle in the yarn take-off direction. Thus the outlet area extends from the outlet opening in the direction in which the finished spun yarn is taken from the air spinning nozzle.

According to the present invention, the navel is arranged in the outlet area downstream of the outlet opening in the yarn take-off direction. The navel can be arranged both directly behind the outlet opening, and in that case in particular directly at a thread channel output or a piecing tube, as well as at a distance from that between the outlet opening and a winding device for winding the air-spun yarn. However, it is preferable for the navel to be the component closest to the outlet opening in the direction of the yarn take-off, i.e. preferably at least no functional component or component acting on the finished spun yarn is arranged between the outlet opening and the navel, preferably with the exception of one or more yarn guiding elements in this area. Furthermore, it is preferable for the navel to be arranged in a locationally fixed and/or rotationally fixed manner at the outlet opening or in the outlet area.

The navel can basically be formed from any material and from any number of components. Preferably, at least the area of the navel that comes into contact with the yarn, and particularly preferably the entire navel, is formed from ceramic and/or in one piece. Furthermore, the navel preferably has, at least in sections and preferably completely, a conical or conically tapered and/or cylindrical shape.

The size and/or geometry of the navel is also preferably adapted to the spun yarn that is to be modified. The inner diameter of the navel or a nozzle opening is preferably between 0.5 mm and 2.5 mm, particularly preferably between 1 mm and 1.5 mm and even more particularly preferably between 1.1 mm and 1.3 mm. Furthermore, the length of the navel or the nozzle opening for taking up the yarn is preferably at least the diameter of the nozzle opening, particularly preferably at least twice the diameter and even more particularly preferably between twice the diameter and ten times the diameter of the nozzle opening. The cross-section of the nozzle opening of the navel can basically be of any shape, although an essentially round cross-section is preferable.

According to the present invention, the navel causes an advantageous surface modification of the air-spun yarn, in which case the surface modification is preferably carried out essentially by friction on the navel surface. The modification of the surface finish preferably includes creating a puffed and/or hairy yarn surface. For this purpose, it is particularly preferable for fiber ends to be created which protrude from the surface of the yarn. The modification of the yarn surface takes place in particular immediately after the air spinning process, i.e. the navel preferably influences the air-spun yarn and in particular its surface finish directly when or after leaving the air spinning nozzle. For this purpose, the spun yarn preferably runs through the navel when it is taken from the air spinning nozzle, and there the desired influence is applied to the yarn surface.

Furthermore, the yarn preferably runs behind the navel over at least one and preferably several take-up rollers and/or through at least one thread monitor and/or through at least one thread clearer and/or over at least one thread guide. The yarn is then preferably wound onto a package.

In a preferable configuration of the spinning position according to the present invention, the navel has a nozzle opening for all-around take-up of the air-spun yarn, in which case particularly advantageous contact can be achieved between the yarn surface and the surface of the navel, and thus particularly effective interaction. An all-around take-up is defined as contact between the nozzle surface of the navel and the yarn surface, in which at least one section of the yarn in the navel is in contact with the nozzle surface on essentially all sides or over the entire circumference.

As per an advantageous further development of the spinning position according to the present invention, the navel, preferably in the area of the nozzle opening and/or in an area coming into contact with a surface of the air-spun yarn, has a structured nozzle surface for mechanical interaction with the surface of the yarn to be modified, thus enabling particularly intensive and effective mechanical interaction. Different degrees and/or forms of structuring are basically possible in this case, in particular depending on the desired surface modification or the surface modification to be obtained as well as depending on the fiber material used in air spinning and/or the thickness of the air-spun yarn. In particular, the navel preferably has several differently structured areas in order to achieve an optimum surface modification. The area of the navel that comes into contact with the yarn surface is particularly preferably a wall area on the inside of the nozzle opening, which is also referred to as the nozzle surface.

As per a particularly advantageous further development of the spinning position according to the present invention, structure elements protruding from the nozzle surface for intensified mechanical interaction with the yarn surface to be modified are arranged in the navel in the area of the nozzle opening, in particular on the structured nozzle surface, by means of which the navel can be adapted in a particularly straightforward manner to the specifically required modification of the yarn surface. The structure elements in this case protrude from the remainder of the nozzle surface and/or opposite a cylindrical base surface of the nozzle opening. The structure elements on the nozzle surface can basically be arranged in a non-ordered or ordered manner, in particular within a grid. The inner diameter of the navel or the diameter of the nozzle opening is preferably selected in such a way that the yarn surface to be modified comes into contact at least with the surfaces of the structure elements. It is particularly preferable for at least contact on all sides of the yarn surface to be modified to be achieved with the surfaces of the structure elements. This contact can be exclusively with the structure elements protruding from the nozzle surface or simultaneously with the remainder of the nozzle surface.

The structure elements can basically be formed as elevations of any shape. Preferably, the structure elements protruding from the nozzle surface are formed as a spiral, rings, crosses, notches, grooves, squares, circles, dots and/or other elevations, in which case the desired properties of the yarn surface can be adjusted in a straightforward manner. All structure elements, however at least those of an area or zone, preferably have a shape, height, size, length and/or width that is/are identical to one another. It is even more particularly preferable for all structure elements, at least those of an area or zone, to be formed identically to one another. However, several different structure elements can also be arranged in one area or zone at the same time. In the case that several different structure elements are arranged, these can be arranged both randomly next to one another as well as according to a defined pattern, for example two different structure elements alternating in at least one spatial direction, in particular along the circumference and/or parallel to the central longitudinal axis of the nozzle opening.

The respective shape of the structure elements protruding from the nozzle surface, for example a cross shape, can relate to the shape of the individual structure element protruding from the surface, i.e. along both directions on the surface of the nozzle opening or on a wall of the navel delimiting the nozzle opening. Alternatively, the respective shape can also basically relate to the shape of the entire nozzle opening, which is formed in particular in this case by several structure elements arranged along the circumference of the nozzle opening, in which case the resulting shape that is particularly preferable is then in a direction along a cross-sectional plane through the nozzle opening, in particular normal to the central longitudinal axis of the nozzle opening.

In the case of an advantageous configuration of the spinning position according to the present invention, protruding structure elements differing from one another are arranged in several zones on the nozzle surface, each of the zones preferably extending over the entire circumference of the nozzle surface and/or the zones being arranged one behind the other in the nozzle opening, in particular along the central longitudinal axis of the nozzle opening, thus enabling an even more precise and effective modification of the yarn surface. A configuration in which the nozzle opening is divided along the central longitudinal axis into at least two zones is even more particularly preferable, the first zone comprising a first shape of the protruding structure elements and/or a constant cross-section of the nozzle opening and the second zone having a different shape of the protruding structure elements and/or a conically widening cross-section of the nozzle opening.

In another advantageous configuration of the spinning position according to the present invention, the navel is fixed so as to be rotatable, in particular about the central longitudinal axis of the nozzle opening, as a result of which the yarn taken from the air spinning nozzle can be drawn or moved through a rotating navel, leading to even stronger interaction with the air-spun yarn, which can be regulated during operation of the spinning position, and thus an even more effective modification of the yarn surface can be achieved in a particularly advantageous manner.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Several embodiment examples of a spinning position according to the present invention, each with different navels, are explained in more detail below with reference to the drawings. In the drawings:

FIG. 1 shows a schematic view of a spinning position of an air spinning machine with a navel arranged behind an air spinning nozzle,

FIG. 2a shows a lateral sectional view of a first embodiment of a navel,

FIG. 2b shows a view of the rear of the navel depicted in FIG. 2 a,

FIG. 3a shows a lateral sectional view of a second embodiment of a navel,

FIG. 3b shows a view of the rear of the navel depicted in FIG. 3 a,

FIG. 4a shows a lateral sectional view of a third embodiment of a navel, and

FIG. 4b shows a view of the rear of the navel depicted in FIG. 4 a.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the embodiments of the present invention is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. The following description is provided herein solely by way of example for purposes of providing an enabling disclosure of the invention, but does not limit the scope or substance of the invention.

At a spinning position 1 of an air spinning machine depicted in FIG. 1, a fiber band 3 is fed to an air spinning nozzle 4 and spun into a yarn 2 here. For this purpose, the fiber band 3 is first stretched by means of a drafting system 16 and then fed to the air spinning nozzle 4 through an inlet opening 5. In the area of the air spinning nozzle 4, there is a blowing air nozzle 18 which swirls the fibers lying outside in the fiber band 3 around fibers in the center of the fiber band 3 and thus forms a yarn 2 by means of the yarn forming element 17. For this purpose, the spinning position 1 has a compressed air system 20 with a compressed air source 21 and a control unit 22.

The yarn 2 produced in this way is then guided from the air spinning nozzle 4 through a thread channel of the yarn forming element 17 to an outlet opening 7 in an outlet area 6 in order to be wound up subsequently. A navel 8 is also arranged in the outlet area 6 downstream of the outlet opening 7 in the yarn take-off direction, through which navel 8 the finished air-spun yarn 2 is drawn by means of a thread take-off device 19 of the spinning position 1. The thread take-off device 19 can be, in particular, a roller pair or take-off roller downstream of the navel 8 in the yarn take-off direction or, in addition alternatively, the thread take-off device 19 can be the winding device for winding a take-up package such as a cross-wound package.

The navel 8 is provided to modify the surface finish of the finished yarn 2 spun in the air spinning nozzle 4, thus generating a softer yarn surface and increased hairiness of the yarn 2, which makes it more suitable as a knitting yarn and allows the production of fabrics with a more pleasant feel.

For this purpose, a first embodiment of a navel 8 depicted in FIG. 2a, b has a nozzle opening 9 through which the finished air-spun yarn 2 is taken, the diameter of the nozzle opening 9 being adapted to the diameter of the yarn 2 drawn through it in such a way that the surface of the yarn 2 can be modified by mechanical interaction and, in particular, by the friction occurring when the yarn 2 is drawn through. The nozzle opening 9 is arranged centrally in the navel 8 in this case.

For this purpose, the navel 8 has a structured, in particular a roughened nozzle surface 10 in at least one zone on the wall of the nozzle opening 9 which comes into contact with the yarn 2. The zone with a structured nozzle surface 10 has a constant diameter over the entire length, which is adapted to the diameter of the yarn 2 to be modified. Furthermore, the wall in the nozzle opening 9 is rotationally symmetrical to the central longitudinal axis A of the navel 8, so that the navel 8 can be used both in a stationary arrangement and without rotation, as well as rotating about the central longitudinal axis A.

In front of this zone with a structured nozzle surface 10, there is an input zone 14 in the yarn take-off direction with a conically narrowing round cross-section (see FIG. 2a ), which allows the air-spun yarn 2 to run into the navel 8 in a particularly straightforward manner, and advantageously prevents the yarn 2 from tearing. This input zone 14 has a smooth, non-structured nozzle surface 23, in which interaction with the air-spun yarn 2, especially the friction, is particularly low.

A further zone 13 is arranged in the yarn take-off direction behind the zone with a structured nozzle surface 10, the cross-section of which zone 13 widens in a non-linear manner, in particular exponentially, and is also round. The nozzle surface 23 is also smooth and unstructured in this embodiment of the navel 8.

A second embodiment of a navel 8 depicted in FIG. 3a, b basically differs from the first embodiment in that identical structure elements 11 protruding from the nozzle surface 10 and forming the structure of the nozzle surface 10 are arranged in the nozzle opening 9 in the area of the first zone 13. In this case, the structure elements 11 are arranged in a grid and have the shape of cuboids protruding from the nozzle surface 10, i.e. a rectangular shape. These structure elements 11 protruding from the nozzle surface 10 enable an intensification of the interaction between the surface of the air-spun yarn 2 to be modified and the wall of the nozzle opening 9.

A third embodiment of a navel 8 depicted in FIG. 4a, b basically differs from the embodiment depicted in FIG. 3a, b in that in the second zone 14 of the nozzle opening 9, which is arranged downstream of the first zone 13 with a structured nozzle surface 10 in the yarn take-off direction, a structured surface of the nozzle opening 9 is also provided, which is a second structure element 12 in the form of a spiral protruding from the nozzle surface.

By means of the spinning position 1, and in particular by means of an air spinning machine with several identical spinning positions 1, an air-spun yarn 2 can be produced in a particularly straightforward manner and without negative influence on the spinning process and the spinning result, which air-spun yarn 2 has significantly better surface properties than a conventionally air-spun yarn and can therefore be used in a much more versatile manner.

To produce an air-spun yarn 2 with a modified surface finish, a fiber band 3 is first stretched in a drafting system 16 and then fed to an inlet opening 5 of an air spinning nozzle 4, where the fiber band 3 is spun into a yarn 2. The spinning position 1 is controlled by means of a control unit 22 to form an optimum yarn 2. The finished spun yarn 2 leaves the air spinning nozzle 4 through a spinning cone 17 and is then drawn through a navel 8 by means of a thread take-off device 19 with several take-up rollers in order to modify the yarn surface or the surface finish of the yarn 2, thereby in particular creating increased hairiness of the yarn surface.

Downstream of the navel 8 and, if applicable, also the thread take-off device 19, the yarn 2 runs through at least one thread monitor and through a thread clearer. The yarn 2 is then wound onto a package.

LIST OF REFERENCE SIGNS

-   -   1 Spinning position     -   2 Yarn     -   3 Fiber band     -   4 Air spinning nozzle     -   5 Inlet opening     -   6 Outlet area     -   7 Outlet opening     -   8 Navel     -   9 Nozzle opening     -   10 Structured nozzle surface     -   11 Structure element     -   12 Second structure element     -   13 First zone     -   14 Second zone     -   16 Drafting system     -   17 Yarn forming element     -   18 Blowing air nozzle     -   19 Thread take-off device     -   20 Compressed air system     -   21 Compressed air source     -   22 Control unit     -   23 Smooth nozzle surface     -   A Central longitudinal axis

It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements. 

What is claimed is:
 1. A spinning position for producing a yarn from a fed fiber band, with an air spinning nozzle with an inlet opening for the fed fiber band and an outlet area with an outlet opening for the air-spun yarn, characterized in that a navel is arranged in the outlet area downstream of the outlet opening in the yarn take-off direction for modifying the surface finish of the spun yarn.
 2. The spinning position according to claim 1, characterized in that the navel has a nozzle opening for all-around take-up of the air-spun yarn.
 3. The spinning position according to claim 1, characterized in that the navel has a structured nozzle surface in the area of the nozzle opening for mechanical interaction with the surface of the yarn to be modified.
 4. The spinning position according to claim 1, characterized in that structure elements protruding from the nozzle surface are arranged in the area of the nozzle opening for intensified mechanical interaction with the yarn surface to be modified.
 5. The spinning position according to claim 1, characterized in that the structure elements protruding from the nozzle surface are formed as a spiral, rings, crosses, notches, grooves, squares, circles, dots, other elevations, or a combination.
 6. The spinning position according to claim 1, characterized in that several zones of protruding structure elements differing from one another are arranged on the nozzle surface, each of the zones extending over the entire circumference of the nozzle surface and/or the zones being arranged one behind the other in the nozzle opening.
 7. The spinning position according to claim 1, characterized in that the nozzle opening is divided along the central longitudinal axis into at least two zones, the first zone comprising a first shape of the protruding structure elements and/or a constant cross-section of the nozzle opening and the second zone having a different shape of the protruding structure elements and/or a conically widening cross-section of the nozzle opening.
 8. The spinning position according to claim 1, characterized in that the navel is fixed so as to be rotatable about the central longitudinal axis of the nozzle opening.
 9. An air spinning machine with at least one spinning position according to claim 1 for producing a yarn from a fed fiber band.
 10. A method for producing a yarn with a modified surface finish, comprising: air spinning of a yarn from a fiber band by an air spinning nozzle, and guiding of the air-spun yarn through a navel for modifying the yarn surface as the air-spun yarn is taken from the air spinning nozzle.
 11. A method of using a navel in the outlet area behind an outlet opening of an air spinning nozzle of a spinning position according to claim 1 for modifying the surface finish of an air-spun yarn. 